Advice on Brown water in bilge

Brabs

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Hello everyone,
I am looking for some advice as to were the brownish water in my bilge on my westerly 33 is coming from, she is berthed in the marina and has been in the water about 9 months after being sailed up from Walton on naze, I haven't checked the bilge for about 3 months having her only sat in the marina, today I noticed a little water in my engine compartment and then traced it back lifting the deck boards, I mopped out 2 buckets of brown water, I dumped the water overboard and what looked like a little sheen of oil was present, could this of come from my engine, it a OM636 Mercedes, I have run the engine in the marina numerous times while doing jobs on the boat, any help would be appreciated
 
A guess the brown colour is rust stain. Is the engine raw water or fresh water cooled? if fresh water have you had to top up the level if not has it lost any but 2 buckets would rule that out anyway, if raw water look for signs of leakage. Next you need to know is it fresh water or sea water if it's sea water then start looking at all sea cocks for signs of leaking, if fresh then it's pointing to a leak from the deck or cockpit.
 
It could be an algal/fungal efflorescence. Slightly warm water in contact with bits of dust, toast, skin flakes etc can develop a soup.

Was the water a consistent colour and cloudiness when you discovered it (i.e. particles or bugs in suspension), or did you have to stir it to achieve a consistent browny colour ?
 
The water was just a brown coloured water, I lifted the deck board forward of the engine compartment next to my table, there was a stainless steel tank about a foot square, haven't a clue what that's for but is empty, oh and the engine is seawater cooled, what could be worst case scenario??
 
Have a taste of it, by which I mean dip your finger in & dab it on your tongue, you'll know straight away whether it's salt water or not. Have a good look round the boat anywhere that water might be able to get in above and below the waterline - stern gland, seacocks, windows, hatches, cockpit locker lids, cockpit floor, deck fittings, etc. Run engine and check for any leaks, the fact that you have run the engine with no problems suggests it's not engine related or if it is it's not serious. Monitor the amount of water, you'll find where it's coming in eventually. Boats get water in and bilges are there to collect it, I wouldn't worry yourself unduly...
 
You don't say how brown the water is, but it's possible that it's rainwater coming in through a deck fitting where the sealant has broken down, with the brown colour being caused by rotting plywood core in the deck mouldings. Hopefully not though, but something to bear in mind if nothing else comes to light.
 
Thanks all for your replies, I will monitor the situation and hopefully its nothing to major, fingers crossed lol
 
The water was just a brown coloured water, I lifted the deck board forward of the engine compartment next to my table, there was a stainless steel tank about a foot square, haven't a clue what that's for but is empty, oh and the engine is seawater cooled, what could be worst case scenario??

Any pipes coming from it? if so follow them and find out if it's water related, could even be a black water tank from the heads :eek:
 
Water leaking in around a keel bolt can be brown as it gets stained by rust on top of the iron keel.
 
Water leaking in around a keel bolt can be brown as it gets stained by rust on top of the iron keel.
Hi Graham
Thanks for your reply, she has been sat in the marina since last July after we sailed her up from down south, would there not be more water? Or is it a slow process
 
To sum up then, the bog is leaking crap everwhere; the engine is knackered and is only good for using as an anchor; the decks are rotting through and not safe to walk on; and the keel is about to fall off. Might be time to sell the boat...... :LOL:
 
Hi Graham
Thanks for your reply, she has been sat in the marina since last July after we sailed her up from down south, would there not be more water? Or is it a slow process
If it is a keel bolt leaking the rust will cause staining of the gel coat or paint around the bolt. A leak can be just a tiny weep barely noticeable in some cases.
 
It is not unusual for stagnant water in the bilge to turn brown. My auto bilge pump does not pump every drop - there is always a small amount that collects ... over time this turns brown ... and when I mop out and put overboard - the water shows a slight sheen ... but I have no oil leaking to there. I suspect its from the GRP, paint and wood formers ....

Last winter I gave the bilges a good scrub and then painted flat white ...... so far no brown water ... but lets see later when the bilge paint starts to break down as I only gave it one thin coat.
 
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